Chronic dynamic exercise increases Apolipoprotein A-I expression in rabbit renal cortex as determined by Proteomic technology

Roger de Moraes ¹, Richard Hemmi Valente ¹, Ileana Rodrigues Leon ¹, Monique Trugilho ¹, Jonas Perales ¹, Antônio Cláudio Lucas Nobrega ² and Eduardo Tibirica ^1*

¹ Oswaldo Cruz Institute, Brazil
² Fluminense Federal University, Brazil

^* To whom correspondence should be addressed. E-mail: etibi{at}ioc.fiocruz.br.

Accepted 9 August 2007

Abstract

Objective: We demonstrated previously that exercise training enhances endothelium-dependent and -independent rabbit kidney vascular relaxation. The present study investigated protein expression changes in the rabbit renal cortex induced by chronic dynamic exercise.

Design: Kidneys were obtained from New Zealand rabbits either pen confined (n=8) or treadmill trained (0% grade) for 5 days/wk at a speed of 18 m/min during 60 min over a 12-week period (n=8). Expression of proteins in the renal cortex was determined by colloidal Coomassie blue staining after two-dimensional polyacrylamide gel electrophoresis. Differencial protein spots were excised, trypsin digested and peptides sequenced by electrospray ionization-ion trap mass spectrometry.

Results: Two pairs of matching differentially stained spots displayed an approximate 3-fold increase in trained animals when compared to sedentary ones. These four spots presented a molecular mass of 23 kDa but different pI values. Mass spectrometric analyses revealed the pairs of matching spots as being rabbit apolipoprotein A-I.

Conclusion: Chronic dynamic exercise increases apolipoprotein A-I expression in the rabbit renal cortex. This fact could be involved in the alterations observed in the renal circulation after exercise training.